Cutter head holder of an underwater granulator

Abstract

A cutter head holder for blades of an underwater granulator for granulating pellets from a plastic melt that emerges from a perforated plate into a process chamber of a housing of an underwater granulator.

What is claimed is: 
     
       1. A cutter head holder for blades of an underwater granulator for granulating pellets from a plastic melt that emerges from a perforated plate into a process chamber in a housing of the underwater granulator, wherein the cutter head holder comprises:
 a. a cutter shaft coupled to a motor shaft of a motor of the underwater granulator, wherein the cutter shaft comprises:
 (i) an inner cutter shaft part, wherein the inner cutter shaft part has a blade holder securing blades to the inner cutter shaft part; 
 (ii) an outer cutter shaft part at least partially disposed about the inner cutter shaft part, wherein the outer cutter shaft part and the inner cutter shaft part are axially displaceable relative to one another, and wherein the inner and the outer cutter shaft parts are prevented from rotating relative to one another; 
 (iii) a front support in a forward region that faces the perforated plate of the underwater granulator so as to be axially displaceable relative to the outer cutter shaft part, wherein the front support supports the outer cutter shaft part, and wherein the outer cutter shaft part is supported to be rotatable relative to the housing of the underwater granulator by at least one rotary bearing; and 
 (iv) a driver element for connecting the inner cutter shaft part to the outer cutter shaft part, wherein the driver element transmits rotational force and axial force between the inner cutter shaft part and the outer cutter shaft part, and further wherein the driver element comprises at least one drive pin connected to both the inner cutter shaft part and the outer cutter shaft part. 
 
 
     
     
       2. The cutter head holder of  claim 1 , wherein the front support is in the forward region of up to 30 percent of a length of the inner cutter shaft part. 
     
     
       3. The cutter head holder of  claim 1 , wherein the front support is a plain bearing. 
     
     
       4. The cutter head holder of  claim 2 , wherein the front support is a plain bearing. 
     
     
       5. The cutter head holder of  claim 1 , wherein the front support is a plain bearing. 
     
     
       6. The cutter head holder of  claim 1 , wherein the outer cutter shaft part is sealed in an axially displaceable manner with respect to the inner cutter shaft part in the region of the front support by an axial seal. 
     
     
       7. The cutter head holder of  claim 1 , wherein the outer cutter shaft part is rotatably sealed with respect to the housing of the underwater granulator by at least one rotary seal. 
     
     
       8. The cutter head holder of  claim 1 , wherein an axial adjusting device is provided, which is connected by the driver element to the inner cutter shaft part. 
     
     
       9. The cutter head holder of  claim 8 , wherein the axial adjusting device has an operating fluid section with at least one cavity facing the housing of the underwater granulator or a housing of the motor and connected to an operating fluid source, so that a suitable axial displacement of the inner cutter shaft part takes place by means of the driver element as a result. 
     
     
       10. The cutter head holder of  claim 9 , wherein the operating fluid section has a double acting cylinder. 
     
     
       11. The cutter head holder of  claim 1 , wherein the outer cutter shaft part is coupled to the motor shaft in a rotationally fixed manner, by a feather key located between the motor shaft and a rear section of the outer cutter shaft part. 
     
     
       12. The cutter head holder of  claim 1 , wherein the blades are mounted on the inner cutter shaft part by a blade holder. 
     
     
       13. The cutter head holder of  claim 1 , further comprising a suspension connected with a housing of the motor, the housing of the underwater granulator, or combinations thereof. 
     
     
       14. The cutter head holder of  claim 1 , further comprising a process chamber housing section and a bearing housing section that is attached thereto by a flange section and to which a housing of the motor is attached.